CHEMSCAN
  • Applications
    • Municipal Water Monitoring >
      • Ammonia Feed
      • Chloramination Control
      • Chlorination
      • Color Analysis
      • Distribution Monitoring
      • Ion Exchange Breakthrough
      • Natural Organic Matter (NOM) Removal
      • Peak Point Chloramination Control
      • Phosphate Sequesterant Feed Control
      • Reservoir Monitoring
      • Security Monitoring
      • TOC Monitoring in Water
      • Well Blending
    • Wastewater Monitoring and Control >
      • Aeration Control and Energy Cost Reduction
      • Biological Nutrient Removal
      • Biological Phosphorus Removal
      • Chemical Phosphorus Removal
      • Chloramination /Breakpoint Avoidance
      • Chlorination/De-Chlorination
      • De-Nitrification Monitoring
      • Nitrification
      • Nutrient Deficiency Analysis
      • Lagoon Discharge
      • SBR Stage Control
      • TOC Monitoring
      • UV Disinfection Control
    • Industrial Water Treatment >
      • Boiler Water Analysis
      • Cooling Water Analysis (Closed Loop)
    • Industrial Process Monitoring >
      • Electroless Plating
    • ASA Technical Papers (ALL)
    • ChemScan Installation Photos
    • Success Stories
    • ChemScan Webinars
  • Service
    • Contact Service Request Form
    • ChemScan Service Team
    • MSDS
    • Communication Protocols
    • Software Utilities
    • Service Videos
  • Parts
  • Company
    • Terms and Conditions
    • Contact Form (General Inquiry)
    • Contact Service
    • Application Data Sheet
    • Employment Opportunities
    • ChemScan Representatives and Distributors
  • Products
    • ChemScan Mini Analyzer >
      • mini oP (Ortho Phosphate)
      • mini oP (Ortho Phosphate) Extended Range
      • mini Cu (Copper)
      • mini LoP (Low Ortho Phosphate)
      • mini UV-254
      • mini LowAm (Low Ammonia)
      • mini Mn (Manganese)
      • mini LowMn (Low Manganese)
      • mini LowChlor (Low Chlorine)
      • mini Sulfite
      • mini Ammonia
      • mini FreeAm (Free Ammonia)
      • mini Fe (Iron)
      • mini Ni (Nickel)
      • mini PAA (Peracetic Acid)
      • mini ChlorAm
    • ChemScan mini Accessories
    • ChemScan Process Analyzers >
      • ChemScan 2150/S Chloramination Analyzer
      • ChemScan 2150/DC Chem Feed Analyzer
      • ChemScan 2150/N Aeration Rate Analyzer
      • ChemScan 2150/NoP Chem Feed Analyzer
      • ChemScan 2150/NHoP Nutrient Analyzer
      • ChemScan 2150 Process Analyzer
      • ChemScan UV-3150 Process Analyzer
      • ChemScan 4100 Nutrient Control
      • ChemScan 6101 Nutrient Control
    • ChemScan Process Analyzers with HMI >
      • ChemScan 2250/S HMI Chloramination Analyzer
      • ChemScan 4200 HMI Analyzer
      • ChemScan 3250 HMI Analyzer
      • ChemScan 2250/NoP HMI Analyzer
      • ChemScan 2250/NHoP HMI Analyzer
      • ChemScan 2250/N HMI Analyzer
      • ChemScan 2250 HMI Analyzer
      • ChemScan 6201 HMI Analyzer
    • ChemScan Analyzer Accessories
    • ChemScan Sensor Family

Hardness in Water

​​​​Standard Analysis

The standard method for hardness analysis requires the addition of EDTA and dye (Calmagite or Eriochrome Black T) at a fixed pH (10.0 ± 0.1) to an aqueous solution. The dye forms a complex with calcium and magnesium, yielding a red color. The EDTA is added as a titrant, causing the solution to change from red to blue and marking the end point of the titration, which is proportionate to the calcium and magnesium content of the sample.

The standard procedure requires careful control of solution pH and some form of automatic titration with colorimetric detection. This method is difficult to automate and not reliable for very low hardness determinations.

ChemScan Analytical Method

The ChemScan method is an improvement of the standard method. The EDTA titration is eliminated and precise pH control is not required as long as sample pH is 12 or more.

The ChemScan Process Analyzer detects the intensity of the reaction between Calmagite indicator and hardness anions (calcium plus magnesium) at multiple wavelengths following addition of a pH buffer. It is reliable at low concentration (0.1 - 4.0 ppm hardness). Results are shown in ppm CaCO3 units.

​Monitoring System Requirements
Principal applications are in cooling or boiler water and low hardness process water.


ChemScan, Inc.
2325 Parklawn Dr., Suite I, Waukesha, Wisconsin, USA 53186
​Phone: 262-717-9500
Toll Free: 800-665-7133
  • Applications
    • Municipal Water Monitoring >
      • Ammonia Feed
      • Chloramination Control
      • Chlorination
      • Color Analysis
      • Distribution Monitoring
      • Ion Exchange Breakthrough
      • Natural Organic Matter (NOM) Removal
      • Peak Point Chloramination Control
      • Phosphate Sequesterant Feed Control
      • Reservoir Monitoring
      • Security Monitoring
      • TOC Monitoring in Water
      • Well Blending
    • Wastewater Monitoring and Control >
      • Aeration Control and Energy Cost Reduction
      • Biological Nutrient Removal
      • Biological Phosphorus Removal
      • Chemical Phosphorus Removal
      • Chloramination /Breakpoint Avoidance
      • Chlorination/De-Chlorination
      • De-Nitrification Monitoring
      • Nitrification
      • Nutrient Deficiency Analysis
      • Lagoon Discharge
      • SBR Stage Control
      • TOC Monitoring
      • UV Disinfection Control
    • Industrial Water Treatment >
      • Boiler Water Analysis
      • Cooling Water Analysis (Closed Loop)
    • Industrial Process Monitoring >
      • Electroless Plating
    • ASA Technical Papers (ALL)
    • ChemScan Installation Photos
    • Success Stories
    • ChemScan Webinars
  • Service
    • Contact Service Request Form
    • ChemScan Service Team
    • MSDS
    • Communication Protocols
    • Software Utilities
    • Service Videos
  • Parts
  • Company
    • Terms and Conditions
    • Contact Form (General Inquiry)
    • Contact Service
    • Application Data Sheet
    • Employment Opportunities
    • ChemScan Representatives and Distributors
  • Products
    • ChemScan Mini Analyzer >
      • mini oP (Ortho Phosphate)
      • mini oP (Ortho Phosphate) Extended Range
      • mini Cu (Copper)
      • mini LoP (Low Ortho Phosphate)
      • mini UV-254
      • mini LowAm (Low Ammonia)
      • mini Mn (Manganese)
      • mini LowMn (Low Manganese)
      • mini LowChlor (Low Chlorine)
      • mini Sulfite
      • mini Ammonia
      • mini FreeAm (Free Ammonia)
      • mini Fe (Iron)
      • mini Ni (Nickel)
      • mini PAA (Peracetic Acid)
      • mini ChlorAm
    • ChemScan mini Accessories
    • ChemScan Process Analyzers >
      • ChemScan 2150/S Chloramination Analyzer
      • ChemScan 2150/DC Chem Feed Analyzer
      • ChemScan 2150/N Aeration Rate Analyzer
      • ChemScan 2150/NoP Chem Feed Analyzer
      • ChemScan 2150/NHoP Nutrient Analyzer
      • ChemScan 2150 Process Analyzer
      • ChemScan UV-3150 Process Analyzer
      • ChemScan 4100 Nutrient Control
      • ChemScan 6101 Nutrient Control
    • ChemScan Process Analyzers with HMI >
      • ChemScan 2250/S HMI Chloramination Analyzer
      • ChemScan 4200 HMI Analyzer
      • ChemScan 3250 HMI Analyzer
      • ChemScan 2250/NoP HMI Analyzer
      • ChemScan 2250/NHoP HMI Analyzer
      • ChemScan 2250/N HMI Analyzer
      • ChemScan 2250 HMI Analyzer
      • ChemScan 6201 HMI Analyzer
    • ChemScan Analyzer Accessories
    • ChemScan Sensor Family